Clutch fob radio



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estes, N. Y., aisignorsfto General Motors'Corporation. Detroit, Mich., acorporation of Dela- Application July 29, 1938, Bofill No. 221,888

dclalmsi is in tuning mechanism for a radio'receiving i set where thetuning condensers are turned by a small motor and-it is essential tohave the rcondensers index accurately to certain points for thereception of dierent stations. f l It is therefore an object of o urinvention to provide interconnecting drive means which will enable theload shaft to stop substantially simultaneously with the cessation ofdrive motor current.

Itis a further object cf our invention to provide a simple clutchmechanism for the above purpose. 4

It is a still further object of our invention to provide a clutch whichmay be mounted directly g5 within the motor housing and therefore willtake up no additional space. I

With the above and other objects in view which will be apparent as thespecification proceeds, the embodiments of our invention will be bestunderstood by reference to the following specification and claims andthe illustrations in the accompanying drawings, in which:

Figure 1 is a side elevation of our device, parts being broken away andshown in section.

Figure2isapartialsectionalviewshowing the clutch in position.

Figuresisaverticalsectionthroughamotor and drive of a modified form ofour invention and, 40 Figurei is an end viewof the device shownin Figure3.

Referring now specifically to the drawing. l indicates ahousing for themotor and drive unit. A bracket l is provided within the housinguponwhich is mounted the motor case l within which are carried the statorlaminae l and field windings lli. The end bells of the casing areprovided with curved flanged openings I2 and also rigidly secured to theinner surface of the bells adjacent these openings are curved flangedmembers Il extending in the opposite direction to the flanges on thebells to cooperate therewith and form a parti-spherical opening withinwhich bearings It and Il are supported. These bearings are formed oftubular sleeves, one end of which has an enlarged outer surface 2l whichis parti-spherical to fit within the curved flanges Il and il.

A motor shaft 22 is trunnioned within the bear- Y ings il and il and hasan enlarged collar porvg tion '24 between the ends for locatingpurposes.

The tubular bearing It extends to and abuts one side of the collar 2l toposition the shaft and prevent endwise movement in one direction.

Armature laminae 28 are placed on the opposite 10 end of the shaft witha flanged clutch disc 28, said laminae and disc being riveted togetherby longitudinal rivets ll and pressed onto the shaft until the assemblymeets the collar'u. The tubular. portion of the bearing Ii is adapted to15 extend to and engage the face of the armature to prevent axialmovement in the other direction so lthat the armature is correctlylocated axially and maintained in that position.

` The outer surface of the clutch disc 28 is ta- 20 pered and adapted tofit within a second flanged A clutch plate 32 whose inner surface istapered to match and form the engaging surface. A spur gear 8l visrotatably and slldably mounted on the extreme surface of the tubularportion of the gg bearing it and has rigidly secured thereto and carriesthe clutch plate I2. A helical spring 35 concentric with the shaft islocated within the hollow formed by the two flanged clutch plates l! andIt and tends" to force them apart and 3g thereby disengage the clutchingsurfaces.

It should be noted at this point that the laminae ofthe armature are notof the same axial length as those of the stator and also that they arenot in alignment therewith but rather are eccen- 35 tric. 'Ihis providesspace for the clutch members to be substantially within one end of themagnetic iield of the stator with the movableplate 32 in such a positionthat the field will exert a force thereon tending to pull it inwardlyando cause the clutch faces to engage and driving to take place. As soonas themagnetic field is deenergiaed the spring Il will cause the clutchl plate. to move away and .break the driving engagement.

The end bell of the motor case is provided with a slot 3B on the endcovering the clutch and adjacent this slot there is supported a stubshaft 8l on the-bracket l. This stub shaft il carries two gears It andl! for reducing the speed 3o of rotation, the said gear Il extendingthrough the slot Il and meshing with the lspur gear and the smaller gear42 rotating therewith meshing with a gear Il on a drive shaft 4I whichis connected to the shaft to be driven which may be u for illustrativepurposes a condenser shaft 4I of a receiver 5G.

Thus when the motor is energized the movable plate 32 will be drawn intoengagement with the rotor disc 28 end the spur gear I4 will drive, butas soon as the current is shut on the spring 3E will immediately causedisengagement and driving-will cease but the rotor may coast to a stopthus providing accurate indexing of the driven shaft.

In Figures 3 and i is shown a modified form of our invention. In thisdesign the motor casing 6 is the same as in the previous showing as arethe stator laminas 8, winding l and bearings it and i8. The rotor shaft22' however in this case of uniform diameter throughout and carries e.series of laminae il pressed thereon. As before, these laminas areeccentric to the stator laminas. A disc t is mounted to rotate on thetubular external surface of the bearing i3 which extends to the rotorlaminations. This disc slightly outside the magnetic field of the statorso that the field will tend to draw it toward the center uponenergization.

Mounted on the opposite end on the tubular portion of the bearing it forrotation thereon is o. second disc 5t, said discs 54 and 58 beingrigidly connected together by rods 58 which extend through longitudinalopenings il inthe rotor lamnations. liso mounted to rotate on thebearlng l@ spur gear 82 in juxtaposition to the disc a lubricated washer84 being provided between the Lspur gear and the case so that the gearmay loe pressed against the washer by the disc 5S to form a drivingcontact and a clutch. Gears Sd, @t and i4 are provided as before fortransmitting power to the driven shaft.

In this instance, when the motor is energized the vili drawn inwardlyand transmit y this motion to disc 56 which will press against the sideof the spur gear 62 and drive the same due to the rotor action on therods 5l. Upon deenerglzation this force will be removed and the frictionbetween these two surfaces will be insumcient for driving.

it be advantageous to :errate the engaging faces of the clutch membersto provide positive engagement and it is within the scope of ourinvention to do so. Further, while the invention is illustrated asapplied to an alternating current motor, may be applied equally well toa direct current motor and it is our intention that the invention be notlimited to merely the alternating current type as it in no wayaffects'the operation of the device.

We claim:

l. In a device of the class described, a drive shaft, a driven shaft,means interconnecting the two shafts for driving the latter from theformer including a clutch, a magnetic field for causing rotation of thefirst shaft adjacent the clutch means to actuate the same whereby thelatter is effected thereby simultaneously with the driving of the firstshaft to complete the drive to the second shaft.

2. In a device of the class described, a motor case, a stator therein, arotor mounted in the case for rotation, driving means rotatably mountedon the rotor shaft and clutch means also mounted on the rotor shaftinterconnecting the rotor and driving means, said clutch means beingdirectly magnetically operated by the stator neld so that it is inengagement for driving when the stator is energized.

3. In a device of the claas described, a shaft adapted to rotate, arotor mounted on the shaft, a clutch member secured to the shaft, asecond clutch member loosely mounted on the shaft and a magnetizablefield surrounding the rotating parte and actlngdirectly to causeengagement of the clutch members whereby the rotor willl be driven andthe clutch parts brought into engagement by the same magnetic field.

4. In a device of the class described, a housing, a stator supportedwithin the housing, a rotor and shaft supported within the statoradapted to be driven by the neld thereof, a second shaft carried by thehousing in spaced relation to the rotor shaft, driving means looselymounted on the rotor, engaging means rigidly connected to said secondshaft to cooperate with said shaft driving means to transmit powerbetween the two shafts, clutch means rigid with the rotor to cooperatewith the loosely mounted means, said loosely mounted means lyingdirectly within the field of the stator and being attracted to engagethe clutch on the rotor to cause the nrst named driving means to rotatewith the rotor shaft and drive the second shaft whenever the neld isenergized.

WILLIAM H. HUTCHINS. CYRIL T. WALLIS.

